import re

res=re.split(r'\s+','a    d   c')
print(res)
res=re.split(r'[\s\,\;]+','a;  , ; , d; , c')
print(res)

def is_valid_email(addr):
    if re.match(r'[a-z.]+@[a-z.]+',addr):
        return True
    else:
        return False
    
# 测试:
assert is_valid_email('someone@gmail.com')
assert is_valid_email('bill.gates@microsoft.com')
assert not is_valid_email('bob#example.com')
assert not is_valid_email('mr-bob@example.com')
print('ok')

def name_of_email(addr):
    m=re.match(r'\<?([a-zA-Z\s]+)\>?[a-zA-Z\s]*\@[a-zA-Z]+\.[a-zA-Z]+',addr)
    return m.group(1)
# 测试:
assert name_of_email('<Tom Paris> tom@voyager.org') == 'Tom Paris'
assert name_of_email('tom@voyager.org') == 'tom'
print('ok')